code: def join_2d_array(xs):
      return ":".join([",".join([str(y) for y in x]) for x in xs])
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import argparse
  import copy
  import numpy
  import shutil
  import tempfile
  from micro_converter import MicroConverter
  from py_proto import mace_pb2
  import run_target
  from utils import util
  from utils import device
  from utils import config_parser
  from utils.target import Target
  from utils.config_parser import ModelKeys
  from utils.util import MaceLogger
  from utils.util import mace_check
  import validate
  import layers_validate
label_desc: Use image node_id 1 for calling a global function with example usage: join_2d_array(xs) and returns: str